[flutter_markdown] enable Wasm support (#8120)

Fix directive in widget code

Author: kevmoo

packages/flutter_markdown/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.7.4+2
+
+* Fixes pub.dev detection of WebAssembly support. 
+
 ## 0.7.4+1
 
 * Makes it so that custom blocks are not limited to being a Column or

packages/flutter_markdown/lib/src/widget.dart

@@ -10,7 +10,7 @@ import 'package:flutter/rendering.dart';
 import 'package:markdown/markdown.dart' as md;
 
 import '../flutter_markdown.dart';
-import '_functions_io.dart' if (dart.library.html) '_functions_web.dart';
+import '_functions_io.dart' if (dart.library.js_interop) '_functions_web.dart';
 
 /// Signature for callbacks used by [MarkdownWidget] when
 /// [MarkdownWidget.selectable] is set to true and the user changes selection.

packages/flutter_markdown/pubspec.yaml

@@ -4,7 +4,7 @@ description: A Markdown renderer for Flutter. Create rich text output,
   formatted with simple Markdown tags.
 repository: https://github.com/flutter/packages/tree/main/packages/flutter_markdown
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+flutter_markdown%22
-version: 0.7.4+1
+version: 0.7.4+2
 
 environment:
   sdk: ^3.3.0